//
//  XCVoiceConverter.m
//  XCLameCafToMp3
//
//  Created by edy on 2023/3/29.
//

#import "XCVoiceConverter.h"
#import "lame.h"

#define KFILESIZE (1 * 1024 * 1024)
@implementation XCVoiceConverter

+ (BOOL)audioToMP3:(NSString *)audioPath mp3File:(NSString *)mp3Path{
    NSLog(@"转码开始---");
    if ([[NSFileManager defaultManager] fileExistsAtPath:mp3Path]) {
        NSLog(@"已经存在---");
        return YES;
    }
    
    CFAbsoluteTime startTime =CFAbsoluteTimeGetCurrent();
    @try {
        int read, write;
        
        FILE *pcm = fopen([audioPath cStringUsingEncoding:1], "rb");  //source 被转换的音频文件位置
        fseek(pcm, 4*1024, SEEK_CUR);                                   //skip file header
        FILE *mp3 = fopen([mp3Path cStringUsingEncoding:1], "wb");  //output 输出生成的Mp3文件位置
        
        const int PCM_SIZE = 8192;
        const int MP3_SIZE = 8192;
        short int pcm_buffer[PCM_SIZE*2];
        unsigned char mp3_buffer[MP3_SIZE];
        
        lame_t lame = lame_init();
        //设置声道1单声道，2双声道
        lame_set_num_channels(lame,1);
        lame_set_in_samplerate(lame, 8000.0);
        lame_set_VBR(lame, vbr_off);
        lame_init_params(lame);
        
        do {
            read = (int)fread(pcm_buffer, 2*sizeof(short int), PCM_SIZE, pcm);
            
            if (read == 0)
                write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);
            else
                write = lame_encode_buffer_interleaved(lame,pcm_buffer, read, mp3_buffer, MP3_SIZE);
            
            fwrite(mp3_buffer, write, 1, mp3);
        } while (read != 0);
        
        lame_close(lame);
        fclose(mp3);
        fclose(pcm);
    
    }
    @catch (NSException *exception) {
        NSLog(@"%@",[exception description]);
    }
    NSLog(@"转码结束----");
    CFAbsoluteTime linkTime = (CFAbsoluteTimeGetCurrent() - startTime);
    NSLog(@"Linked in %f ms", linkTime *1000.0);
    
    if (![[NSFileManager defaultManager] fileExistsAtPath:mp3Path]) {
        return NO;
    }
    return YES;
}

@end
 
